In the processing and preparation of parts of poultry and animals such as poultry thighs for sale and consumption in the retail market, such as in restaurants and grocery stores, it is highly desirable to package and serve the meat with the bones removed. Deboned meat can be easily cut-up and used in sandwiches or other food products where it is desirable to have the bones previously removed prior to cooking and serving.
An additional advantage of removing the bones from the meat during processing and before cooking is that the bones do not have to be cooked with the meat, thereby conserving heat energy.
In the past, automated processes have been developed for the removal of meat from the bone of a poultry part, such as from the thigh bone of a poultry thigh, by engaging the bone with a scraping tool and scraping along the length of the bone. For example, U. S. Pat. Nos. 3,672,000, 4,327,463, 4,495,675, 4,736,492 and 5,001,812 disclose deboning apparatus having two or more notched scraping blades which surround the bone. The blades are closed about the bone with the notches of the blades straddling the bone, and the bone is moved longitudinally through the blades. As the bone is moved through the notched blades, the blades progressively strip the meat from the bone.
However, the raw meat has a tendency to cling tightly to the bone. Consequently, it is necessary for the scraper blades to closely surround the thigh bones to ensure the meat is completely stripped from the bone. A problem that arises with such prior art deboners is that the blades should avoid contact with the bone to avoid gouging or chipping the bones as they strip the meat from the bones. This contact between the hard blade material and the bones increases the tendency of creating bone fragments that can become lodged in the stripped meat, which creates a health risk to the ultimate consumer who expects that when he or she purchases a "boneless" product, it is indeed completely boneless.
In order to avoid the creation of bone fragments during the deboning process, apertured elastic meat stripper disks have been substituted for the scraper blades in some stripping equipment. The bone is pushed longitudinally through the aperture of the disk and the resilient disk retards the movement of the meat, thereby separating the meat from the bone. U.S. Pat. No. 4,811,456 teaches the use of an elastic disk for deboning poultry parts.
Additionally, U.S. Pat. No. 5,173,076 discloses an automated deboning apparatus which includes a series of elastic stripping disks, each of which is mounted adjacent and moves with a conveyor tray on which a poultry thigh is received and moved about a processing path. As each thigh is moved along the processing path, the thigh bone is urged through an opening in a stripper disk, whereupon the meat of the thigh is progressively stripped from its bone.
U.S. Pat. No. 5,782,685 (08/782,876) discloses an automated deboning apparatus which includes a tray conveyor having a series of trays for transporting poultry parts along a loading path and then around a horizontally oriented cam drum where deboning modules revolve about the cam drum and register with each tray and its poultry thigh and debone the thigh. The bone of each thigh is pushed through the opening of a stripper disk so that the meat is retarded as the bone passes through the opening of the disk.
A problem sometimes experienced with conveyor/cam drum systems is that there must be a space between the stripper disk and its tray to allow the meat removed from the bone to have room to be separated from the tray and disk, but the space between the tray and disk should not be so large as to sometimes allow the bone to become misaligned between the tray and disk, resulting in improper deboning and possible breaking of the thigh bone.
Accordingly, it can be seen that it would be desirable to provide an improved method and apparatus for cleanly and completely scraping the meat from the thigh bones of poultry parts or similar animal parts without the risk of creating broken bones or improperly deboned products and for providing adequate clearance in the apparatus for removing the meat and bones from the apparatus.